Sierra Mae LaMar was last seen at approximately 6:00 a.m. on March 16, 2012, in the area of Santa Teresa Avenue and Dougherty Avenue in Morgan Hill, California. At that time, she was preparing to leave her home on foot on her way to catch the bus to school. Sierra never made it to the bus or school that morning and has not been heard from since that time.

Sierra Mae LaMar was last seen wearing a black "San Jose Sharks" (hockey team) sweatshirt with the Sharks logo on the front and "STONEHOUSE" and the number "16" on the back. She currently attends Sobrato High School in Morgan Hill, California, and used to attend Washington High School in Fremont, California.